Electron Microscopy of Skeletal Aging

Abstract

Several ultrastructural studies of aging cartilage are known (Barnett et al., 1963; Silberberg et al., 1961, 1964, 1970), and a few electron microscopic studies have been reported on bone aging per se (Tonna, 1972a,b, 1973a-c, 1974b, 1975a,b, 1976b, 1978, 1979). The paucity of the literature understandably stems from the technical burdens of aging studies, and the problem of finding suitable animal models. An animal colony must be bred by the investigator for years at significant cost in advance of commencing an experiment in order to reap sufficient animal numbers to constitute a study. Aged animals of suitable quality and recorded birth dates usually cannot be purchased. Furthermore, the studies are generally long-term and technically more difficult to execute and especially to interpret. Existence of these caveats does not, however, justify our ignorance of the ultrastructural changes of aging skeletal tissues when significant biomedical problems exist concomitant with, or in a cause and effect or contributional relationship with, aging. Such problems are an integral part of known skeletal and degenerative joint diseases, to physiologic imbalances, as well as to biomechanical problems with congenital and growth anomalies or surgical and accidental perturbations. In oral biology, alveolar bone loss in association with periodontal disease and aging is paramount to gerodontics. Knowledge of age changes is not exclusively significant to biomedical gerontology and geriatrics, but scientific information regarding the entire life cycle of cells and their matrices is necessary to a fuller understanding of the behavior and response potential of these bioelements to natural environmental and induced stresses of all types experienced throughout the life span of the individual.